Farseer Physics Engine

New Post: Difficulties with implementation of DebugView

Wizard999 — Sat, 25 May 2013 18:19:40 GMT

I added the project "Farseer Physics Engine 3.3.1 HelloWorld XNA\DebugView XNA\DebugView XNA.csproj" to my solution explorer in Visual Studio. In addition, I added a reference to my project and the "using FarseerPhysics.DebugViews;" to my class.

But DebugView is still not working. I tried this code but I always get an error message and a warning. I found the code in another discussion:
https://farseerphysics.codeplex.com/discussions/275582
Error message: 'FarseerPhysics.DebugViews.DebugViewXNA' does not contain a definition for 'DebugPanel' and no extension method 'DebugPanel' accepting a first argument of type 'FarseerPhysics.DebugViews.DebugViewXNA' could be found (are you missing a using directive or an assembly reference?)
Warning: The referenced component 'DebugView XNA Content (Content)' could not be found.
What is this DebugPanel? What is wrong?

What should I change in my code?

Code:

World world;
DebugViewXNA physicsDebug;
DebugViewXNA DebugViewFlags;
physicsDebug = new DebugViewXNA(world);
physicsDebug.AppendFlags(DebugViewFlags.DebugPanel);
physicsDebug.DefaultShapeColor = Color.White;
physicsDebug.SleepingShapeColor = Color.LightGray;
physicsDebug.LoadContent(GraphicsDevice, Content);

Drawing DebugView:

// calculate the projection and view adjustments for the debug view
        Matrix projection = Matrix.CreateOrthographicOffCenter(0f, graphics.GraphicsDevice.Viewport.Width / _displayUnitsToSimUnitsRatio,
                                                         graphics.GraphicsDevice.Viewport.Height / _displayUnitsToSimUnitsRatio, 0f, 0f,
                                                         1f);
        Matrix view = Matrix.CreateTranslation(new Vector3((_cameraPosition / _displayUnitsToSimUnitsRatio) - (_screenCenter / _displayUnitsToSimUnitsRatio), 0f)) * Matrix.CreateTranslation(new Vector3((_screenCenter / _displayUnitsToSimUnitsRatio), 0f));
        // draw the debug view
        physicsDebug.RenderDebugData(ref projection, ref view);

New Post: Difficulties with implementation of DebugView

Wizard999 — Sat, 25 May 2013 18:19:40 GMT

World world;
DebugViewXNA physicsDebug;
DebugViewXNA DebugViewFlags;
physicsDebug = new DebugViewXNA(world);
physicsDebug.AppendFlags(DebugViewFlags.DebugPanel);
physicsDebug.DefaultShapeColor = Color.White;
physicsDebug.SleepingShapeColor = Color.LightGray;
physicsDebug.LoadContent(GraphicsDevice, Content);

Drawing DebugView:

// calculate the projection and view adjustments for the debug view
        Matrix projection = Matrix.CreateOrthographicOffCenter(0f, graphics.GraphicsDevice.Viewport.Width / _displayUnitsToSimUnitsRatio,
                                                         graphics.GraphicsDevice.Viewport.Height / _displayUnitsToSimUnitsRatio, 0f, 0f,
                                                         1f);
        Matrix view = Matrix.CreateTranslation(new Vector3((_cameraPosition / _displayUnitsToSimUnitsRatio) - (_screenCenter / _displayUnitsToSimUnitsRatio), 0f)) * Matrix.CreateTranslation(new Vector3((_screenCenter / _displayUnitsToSimUnitsRatio), 0f));
        // draw the debug view
        physicsDebug.RenderDebugData(ref projection, ref view);

New Post: OnCollision works not correctly

Wizard999 — Fri, 24 May 2013 15:34:16 GMT

"Coin_OnCollision" is released directly after the start of the game. But there could be no collision between playerrect and a coin, because the start position of playerrect is completely different from the coin position.
I don't know why "Coin_OnCollision" is released. Why is it released after the start of the game?
It should just be released when there is a collision between the playerrect and a coin. After the collision, the coin should be removed.
What is wrong? I don't want that "Coin_OnCollision" is released at the start of the game.

Game1:

public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;
        World world;
        Body playerrect;
        Texture2D playerSprite, coinSprite;
        public List<Coins> CoinsList = new List<Coins>();

        private static float _displayUnitsToSimUnitsRatio = 100f;

        public static Vector2 ToDisplayUnits(Vector2 simUnits)
        {
            return simUnits * _displayUnitsToSimUnitsRatio;
        }

        private bool isOnGround;

        bool Player_OnCollision(Fixture fixtureA, Fixture fixtureB, FarseerPhysics.Dynamics.Contacts.Contact contact)
        {
    //        if (fixtureB.CollisionCategories == Category.Cat5)
            {
        //          isOnGround = true;
            }
        return true;
        }

        void Player_OnSeparation(Fixture fixtureA, Fixture fixtureB)
        {
            if (fixtureB.CollisionCategories == Category.Cat5)
            {
                isOnGround = false;
            }
        }

        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
        }

        protected override void Initialize()
        {
            base.Initialize();
        }

        protected override void LoadContent()
        {
            spriteBatch = new SpriteBatch(GraphicsDevice);
            playerSprite = Content.Load<Texture2D>("retromario");
            coinSprite = Content.Load<Texture2D>("mariocoin");

            if (world == null)
            {
                world = new World(new Vector2(0, 2));
            }
            else
            {
                world.Clear();
            }

            playerrect = BodyFactory.CreateRectangle(world, 0.64f, 0.64f, 1.0f);
            playerrect.BodyType = BodyType.Dynamic;
            playerrect.Position = new Vector2(0.22f, 0f);
            playerrect.CollisionCategories = Category.Cat15;
            playerrect.FixedRotation = true;

            playerrect.OnCollision += Player_OnCollision;
            playerrect.OnSeparation += Player_OnSeparation;

            CoinsList.Add(new Coins(world, BodyFactory.CreateRectangle(world, 0.64f, 0.64f, 1.0f), BodyType.Static, true, new Vector2(1.60f, 4.16f), 0, false, playerrect));
        }

        protected override void Update(GameTime gameTime)
        {
            float elapsed = (float)gameTime.ElapsedGameTime.TotalSeconds;
            world.Step(Math.Min(elapsed, (1f / 60f)));
            for (int i = 0; i <= CoinsList.Count -1; i++)
            {
                if (CoinsList[i].Remove == true)
                    CoinsList.Remove(CoinsList[i]);
            }
            base.Update(gameTime);
        }

        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);
            spriteBatch.Begin();
            for (int i = 0; i <= CoinsList.Count -1; i++)
                {
                    CoinsList[i].Draw(spriteBatch,coinSprite);
                }
            spriteBatch.Draw(playerSprite, ConvertUnits.ToDisplayUnits(playerrect.Position), null, Color.White, playerrect.Rotation, new Vector2(playerSprite.Width / 2.0f, playerSprite.Height / 2.0f), 1f, SpriteEffects.None, 0f);
           spriteBatch.End();

            base.Draw(gameTime);
        }
    }

Coin class:

public class Coins
    {
       Body Coin;
       BodyType Cointype;
       Vector2 Coinposition;
       float Coinrotation;
       public bool Remove;
       World world1;
       Body playerrect;

       public Coins(World world,Body coin, BodyType cointype, bool coinsensor, Vector2 coinposition, float coinrotation, bool remove, Body playerr)
       {
         playerrect = playerr;
         world1 = world;
         this.Coin = coin;
         this.Cointype = cointype;
         this.Coin.IsSensor = coinsensor;
         this.Coinposition = coinposition;
         this.Coinrotation = coinrotation;
         this.Remove = remove;
         Coin.OnCollision += Coin_OnCollision;
       }

         bool Coin_OnCollision(Fixture fixtureA, Fixture fixtureB, FarseerPhysics.Dynamics.Contacts.Contact contact)
        {
           if (fixtureB.CollisionCategories == Category.Cat15)
            {
                world1.RemoveBody(fixtureA.Body);
                Remove = true;
            }
            return true;
        }

        public void Draw(SpriteBatch batch, Texture2D coinSprite)
        {
            if (Remove == false)
            {
              batch.Draw(coinSprite, ConvertUnits.ToDisplayUnits(Coinposition), null, Color.White, Coinrotation, new Vector2(coinSprite.Width / 2.0f, coinSprite.Height / 2.0f), 1f, SpriteEffects.None, 0f);
            }
        }
   }

New Post: OnCollision works not correctly

Wizard999 — Fri, 24 May 2013 15:34:16 GMT

public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;
        World world;
        Body playerrect;
        Texture2D playerSprite, coinSprite;
        public List<Coins> CoinsList = new List<Coins>();

        private static float _displayUnitsToSimUnitsRatio = 100f;

        public static Vector2 ToDisplayUnits(Vector2 simUnits)
        {
            return simUnits * _displayUnitsToSimUnitsRatio;
        }

        private bool isOnGround;

        bool Player_OnCollision(Fixture fixtureA, Fixture fixtureB, FarseerPhysics.Dynamics.Contacts.Contact contact)
        {
    //        if (fixtureB.CollisionCategories == Category.Cat5)
            {
        //          isOnGround = true;
            }
        return true;
        }

        void Player_OnSeparation(Fixture fixtureA, Fixture fixtureB)
        {
            if (fixtureB.CollisionCategories == Category.Cat5)
            {
                isOnGround = false;
            }
        }

        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
        }

        protected override void Initialize()
        {
            base.Initialize();
        }

        protected override void LoadContent()
        {
            spriteBatch = new SpriteBatch(GraphicsDevice);
            playerSprite = Content.Load<Texture2D>("retromario");
            coinSprite = Content.Load<Texture2D>("mariocoin");

            if (world == null)
            {
                world = new World(new Vector2(0, 2));
            }
            else
            {
                world.Clear();
            }

            playerrect = BodyFactory.CreateRectangle(world, 0.64f, 0.64f, 1.0f);
            playerrect.BodyType = BodyType.Dynamic;
            playerrect.Position = new Vector2(0.22f, 0f);
            playerrect.CollisionCategories = Category.Cat15;
            playerrect.FixedRotation = true;

            playerrect.OnCollision += Player_OnCollision;
            playerrect.OnSeparation += Player_OnSeparation;

            CoinsList.Add(new Coins(world, BodyFactory.CreateRectangle(world, 0.64f, 0.64f, 1.0f), BodyType.Static, true, new Vector2(1.60f, 4.16f), 0, false, playerrect));
        }

        protected override void Update(GameTime gameTime)
        {
            float elapsed = (float)gameTime.ElapsedGameTime.TotalSeconds;
            world.Step(Math.Min(elapsed, (1f / 60f)));
            for (int i = 0; i <= CoinsList.Count -1; i++)
            {
                if (CoinsList[i].Remove == true)
                    CoinsList.Remove(CoinsList[i]);
            }
            base.Update(gameTime);
        }

        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);
            spriteBatch.Begin();
            for (int i = 0; i <= CoinsList.Count -1; i++)
                {
                    CoinsList[i].Draw(spriteBatch,coinSprite);
                }
            spriteBatch.Draw(playerSprite, ConvertUnits.ToDisplayUnits(playerrect.Position), null, Color.White, playerrect.Rotation, new Vector2(playerSprite.Width / 2.0f, playerSprite.Height / 2.0f), 1f, SpriteEffects.None, 0f);
           spriteBatch.End();

            base.Draw(gameTime);
        }
    }

Coin class:

public class Coins
    {
       Body Coin;
       BodyType Cointype;
       Vector2 Coinposition;
       float Coinrotation;
       public bool Remove;
       World world1;
       Body playerrect;

       public Coins(World world,Body coin, BodyType cointype, bool coinsensor, Vector2 coinposition, float coinrotation, bool remove, Body playerr)
       {
         playerrect = playerr;
         world1 = world;
         this.Coin = coin;
         this.Cointype = cointype;
         this.Coin.IsSensor = coinsensor;
         this.Coinposition = coinposition;
         this.Coinrotation = coinrotation;
         this.Remove = remove;
         Coin.OnCollision += Coin_OnCollision;
       }

         bool Coin_OnCollision(Fixture fixtureA, Fixture fixtureB, FarseerPhysics.Dynamics.Contacts.Contact contact)
        {
           if (fixtureB.CollisionCategories == Category.Cat15)
            {
                world1.RemoveBody(fixtureA.Body);
                Remove = true;
            }
            return true;
        }

        public void Draw(SpriteBatch batch, Texture2D coinSprite)
        {
            if (Remove == false)
            {
              batch.Draw(coinSprite, ConvertUnits.ToDisplayUnits(Coinposition), null, Color.White, Coinrotation, new Vector2(coinSprite.Width / 2.0f, coinSprite.Height / 2.0f), 1f, SpriteEffects.None, 0f);
            }
        }
   }

New Post: Games That Use Farseer Physics Engine 3.x

TerraCo — Thu, 23 May 2013 05:35:12 GMT

Granny Bash

Early work in progress. Currently being developed for Windows using XNA, Farseer and tIDE. The game doesn't have a definite direction at the moment and is being developed gradually in my spare time while not working (paid 9-5 work, that is).

Blog: http://grannybash.blogspot.com.au/
Steam Greenlight: http://steamcommunity.com/sharedfiles/filedetails/?id=145837379

New Post: How can I create polygons in Farseer 3.3.1?

Wizard999 — Wed, 22 May 2013 20:21:35 GMT

Thanx. That helped me a lot.

New Post: How can I create polygons in Farseer 3.3.1?

Wizard999 — Wed, 22 May 2013 20:21:35 GMT

Thanx. That helped me a lot.

New Post: Fence post joint

TerraCo — Wed, 22 May 2013 06:06:12 GMT

Disregard, fixed it...

JointFactory.CreateFixedRevoluteJoint(_world, _obstacleFixtures[0].Body, _obstacleFixtures[0].Body.LocalCenter - new Vector2(obstacle.Width/2/_pixelsPerMeter,0), new Vector2(20,20));

Will leave this up for anyone else who needs it.

Also, I have shoehorned a few different systems into my game. Farseer Physics and tIDE. There's a couple of layers that do different things (map background, spawn entities). If anyone wants to have a look at the current progress and to see how I implemented the fence joint, visit http://grannybash.blogspot.com.au

Please don't hesitate to ask if you want help marrying up Farseer and tIDE with XNA.

New Post: Fence post joint

TerraCo — Wed, 22 May 2013 06:06:12 GMT

Disregard, fixed it...

JointFactory.CreateFixedRevoluteJoint(_world, _obstacleFixtures[0].Body, _obstacleFixtures[0].Body.LocalCenter - new Vector2(obstacle.Width/2/_pixelsPerMeter,0), new Vector2(20,20));

New Post: Fence post joint

TerraCo — Wed, 22 May 2013 05:36:01 GMT

Hey,

I am looking for the correct type of joint to simulate a fence rotating around a post in birds-eye perspective. Closest thing I have is a singular fence rotating on its point of origin, code below.

public void AddFence(float x, float y)
        {
            // Create a fence
            Fixture Temp = FixtureFactory.CreateRectangle(_world, obstacle.Width / _pixelsPerMeter, obstacle.Height / _pixelsPerMeter, 1);
            Temp.Body.Mass = 100;
            Temp.Body.LocalCenter = new Vector2(300, 0);
            Temp.Body.Position = new Vector2(x * 2.5f, y * 2.5f);
            Temp.Body.Rotation = 90 * ((float)Math.PI / 180);
            Temp.Body.BodyType = BodyType.Dynamic;
            Temp.Body.LocalCenter = new Vector2(10, 0);
            Temp.Body.FixedRotation = false;
            _obstacleFixtures.Add(Temp);
            JointFactory.CreateAngleJoint(_world, _obstacleFixtures[0].Body,LevelBodies[10,10].Body);
        }
public override void Update()
{
_obstacleFixtures[0].Body.Position = LevelBodies[9, 10].Body.Position + new Vector2(0, -obstacle.Width / 2 / _pixelsPerMeter);
}

There's a fair chance that I just don't know the exact type of joint needed

New Post: Fence post joint

TerraCo — Wed, 22 May 2013 05:36:01 GMT

public void AddFence(float x, float y)
        {
            // Create a fence
            Fixture Temp = FixtureFactory.CreateRectangle(_world, obstacle.Width / _pixelsPerMeter, obstacle.Height / _pixelsPerMeter, 1);
            Temp.Body.Mass = 100;
            Temp.Body.LocalCenter = new Vector2(300, 0);
            Temp.Body.Position = new Vector2(x * 2.5f, y * 2.5f);
            Temp.Body.Rotation = 90 * ((float)Math.PI / 180);
            Temp.Body.BodyType = BodyType.Dynamic;
            Temp.Body.LocalCenter = new Vector2(10, 0);
            Temp.Body.FixedRotation = false;
            _obstacleFixtures.Add(Temp);
            JointFactory.CreateAngleJoint(_world, _obstacleFixtures[0].Body,LevelBodies[10,10].Body);
        }
public override void Update()
{
_obstacleFixtures[0].Body.Position = LevelBodies[9, 10].Body.Position + new Vector2(0, -obstacle.Width / 2 / _pixelsPerMeter);
}

There's a fair chance that I just don't know the exact type of joint needed

New Post: How can I use the ContactListener?

benblo — Tue, 21 May 2013 08:49:31 GMT

Here's how I do it:

    // do this on whatever constructor / init function you have
    void Start()
    {
        // get the world singleton somehow
        World world = FSWorldComponent.PhysicsWorld;

        // register
        world.ContactManager.BeginContact += onBeginContact;
        world.ContactManager.EndContact += onEndContact;
        world.ContactManager.PreSolve += onPreSolve;
        world.ContactManager.PostSolve += onPostSolve;

        // NOTE: you should probably unregister on destructor or wherever is relevant...
    }

    bool onBeginContact( Contact _contact )
    {
        // ...
        return true; // or false to ignore the contact
    }
    void onEndContact( Contact _contact )
    {
        // ...
    }

    void onPreSolve( Contact _contact, ref Manifold _oldManifold )
    {
        // ...
    }
    void onPostSolve( Contact _contact, ContactVelocityConstraint _impulse )
    {
        // ...
    }

I use the Unity port of Farseer so your mileage may vary.

New Post: How can I use the ContactListener?

benblo — Tue, 21 May 2013 08:49:31 GMT

Here's how I do it:

    // do this on whatever constructor / init function you have
    void Start()
    {
        // get the world singleton somehow
        World world = FSWorldComponent.PhysicsWorld;

        // register
        world.ContactManager.BeginContact += onBeginContact;
        world.ContactManager.EndContact += onEndContact;
        world.ContactManager.PreSolve += onPreSolve;
        world.ContactManager.PostSolve += onPostSolve;

        // NOTE: you should probably unregister on destructor or wherever is relevant...
    }

    bool onBeginContact( Contact _contact )
    {
        // ...
        return true; // or false to ignore the contact
    }
    void onEndContact( Contact _contact )
    {
        // ...
    }

    void onPreSolve( Contact _contact, ref Manifold _oldManifold )
    {
        // ...
    }
    void onPostSolve( Contact _contact, ContactVelocityConstraint _impulse )
    {
        // ...
    }

I use the Unity port of Farseer so your mileage may vary.

New Post: Games That Use Farseer Physics Engine 3.x

nkast — Tue, 21 May 2013 07:54:53 GMT

Pinball league: The World of Dr. Pickaxe

Pinball game for Windows Phone & Windows Store.
Developed on XNA/monoGame.

Dr Pickaxe for Windows Phone:
http://tainicom.net/games/pinball-league-the-world-of-dr-pickaxe.aspx

Dr Pickaxe for Windows 8/RT:
http://tainicom.net/games/pinball-league-the-world-of-dr-pickaxe-hd.aspx

New Post: How can I create polygons in Farseer 3.3.1?

streikbrecher — Tue, 21 May 2013 07:47:18 GMT

Look at the specs! Its (data, width, holeDetection), so change it to

Vertices  verts = PolygonTools.CreatePolygon(data, polygonTexture.Width, true);

But I highly recommend to look at the farseer samples project. There, AdvancedDemo1 greatly explains how to make an physical object out of a texture.

New Post: How can I create polygons in Farseer 3.3.1?

streikbrecher — Tue, 21 May 2013 07:47:18 GMT

Look at the specs! Its (data, width, holeDetection), so change it to

Vertices  verts = PolygonTools.CreatePolygon(data, polygonTexture.Width, true);

But I highly recommend to look at the farseer samples project. There, AdvancedDemo1 greatly explains how to make an physical object out of a texture.

New Post: How can I create polygons in Farseer 3.3.1?

Wizard999 — Tue, 21 May 2013 07:35:38 GMT

Thanx. But I still have difficulties with this line:

 //Find the vertices that makes up the outline of the shape in the texture
          Vertices  verts = PolygonTools.CreatePolygon(data, polygonTexture.Width, polygonTexture.Height, true);

No overload for method 'CreatePolygon' takes 4 arguments

What should I change in this line?

New Post: How can I create polygons in Farseer 3.3.1?

Wizard999 — Tue, 21 May 2013 07:35:38 GMT

Thanx. But I still have difficulties with this line:

 //Find the vertices that makes up the outline of the shape in the texture
          Vertices  verts = PolygonTools.CreatePolygon(data, polygonTexture.Width, polygonTexture.Height, true);

No overload for method 'CreatePolygon' takes 4 arguments

What should I change in this line?

New Post: How can I create polygons in Farseer 3.3.1?

streikbrecher — Mon, 20 May 2013 23:15:50 GMT

Try changing

List<Fixture> compund = FixtureFactory.CreateCompoundPolygon(world, _list, 1);
compund[0].Body.BodyType = BodyType.Dynamic;

Body body = BodyFactory.CreateCompoundPolygon(world, _list, 1);
body.BodyType = BodyType.Dynamic;

New Post: How can I create polygons in Farseer 3.3.1?

streikbrecher — Mon, 20 May 2013 23:15:50 GMT

Try changing

List<Fixture> compund = FixtureFactory.CreateCompoundPolygon(world, _list, 1);
compund[0].Body.BodyType = BodyType.Dynamic;

Body body = BodyFactory.CreateCompoundPolygon(world, _list, 1);
body.BodyType = BodyType.Dynamic;